CVE-2026-65049: Ninja Forms Auth Bypass Vulnerability

CVE-2026-65049 Overview

CVE-2026-65049 is an incorrect authorization vulnerability [CWE-863] in the Ninja Forms plugin for WordPress Multisite, affecting version 3.14.8 and prior. A subsite Administrator can trigger network-wide deletion of all Ninja Forms data by exploiting a site-scoped capability check combined with unsafe multisite migration defaults. The flaw resides in the nf_delete_all_data AJAX action, which invokes migration routines that iterate every blog in the network via switch_to_blog(). Exploitation drops all nf3_* tables and clears related options and transients across every subsite without requiring super-admin or network-admin privileges.

Critical Impact
A single subsite Administrator can permanently destroy all Ninja Forms data across every site in a WordPress Multisite network through one crafted request to admin-ajax.php.

Affected Products

Ninja Forms plugin for WordPress version 3.14.8 and prior
WordPress Multisite installations running vulnerable Ninja Forms versions
All subsites within a network that share the vulnerable plugin

Discovery Timeline

2026-07-21 - CVE-2026-65049 published to NVD
2026-07-21 - Last updated in NVD database

Technical Details for CVE-2026-65049

Vulnerability Analysis

The vulnerability stems from a mismatch between the scope of the authorization check and the scope of the action performed. Ninja Forms exposes the nf_delete_all_data action via admin-ajax.php, protected by a per-site nonce and a capability check that validates the caller is an Administrator on the current subsite. The underlying handler then invokes migration routines designed to purge Ninja Forms data. These routines iterate every blog in the multisite network using switch_to_blog(), dropping all nf3_* tables and clearing options and transients on each subsite. The site-scoped check never validates whether the caller holds network-level privileges such as manage_network or super-admin status. This is a classic incorrect authorization pattern [CWE-863] where local privileges are treated as sufficient for a global operation.

Root Cause

The root cause is the unsafe default in the multisite migration logic combined with a scope mismatch in authorization. The AJAX handler trusts the standard Administrator capability on the current blog and then executes destructive operations across all blogs. No super-admin gate, no per-blog capability recheck inside the switch_to_blog() loop, and no confirmation step guard the destructive path.

Attack Vector

An authenticated subsite Administrator sends a crafted POST request to admin-ajax.php with action=nf_delete_all_data and a valid per-site nonce obtained from any admin page they can access. The request triggers the migration routine, which walks every blog in the network and executes DROP TABLE statements against nf3_* tables while purging associated options and transients. The result is irreversible data loss for every Ninja Forms installation on the network. Because the required privilege is only Administrator on a single subsite, tenant isolation in shared multisite hosting environments is broken.

See the VulnCheck Ninja Forms Advisory for technical details on the vulnerable handler.

Detection Methods for CVE-2026-65049

Indicators of Compromise

POST requests to /wp-admin/admin-ajax.php containing the parameter action=nf_delete_all_data
Sudden disappearance of nf3_* tables across multiple subsite databases within a short window
Ninja Forms admin pages returning empty form lists on subsites that previously contained forms
Deletion of Ninja Forms options and transients from the wp_options table on multiple blogs

Detection Strategies

Alert on any HTTP POST to admin-ajax.php where the body includes action=nf_delete_all_data, regardless of source subsite
Monitor MySQL general or audit logs for DROP TABLE statements matching the nf3_% pattern executed in rapid succession across databases
Correlate WordPress user session activity with subsequent Ninja Forms table removal events to identify the initiating account

Monitoring Recommendations

Enable WordPress activity logging plugins that capture AJAX action names and originating user IDs
Forward web server access logs and database audit logs to a centralized SIEM for cross-subsite correlation
Baseline the expected count of nf3_* tables per subsite and alert on unexpected schema changes

How to Mitigate CVE-2026-65049

Immediate Actions Required

Update the Ninja Forms plugin to a version later than 3.14.8 on all multisite networks
Audit subsite Administrator accounts and remove any accounts that do not require Administrator privileges
Back up all nf3_* tables and Ninja Forms-related options before applying updates or investigating suspected exploitation
Restrict access to admin-ajax.php from untrusted networks where feasible

Patch Information

Review the WordPress Ninja Forms Changelog for the fixed version and apply the update through the WordPress Ninja Forms Plugin page. The fix scopes the destructive action to super-admin or network-admin privileges and prevents the migration routine from iterating all blogs when triggered from a subsite context.

Workarounds

Temporarily deactivate Ninja Forms network-wide until the patched version is deployed
Use a Web Application Firewall rule to block POST requests to admin-ajax.php containing action=nf_delete_all_data unless originating from a verified super-admin session
Limit subsite Administrator role assignments to trusted operators only
Restrict the manage_options capability on subsites through a must-use plugin that enforces network-admin verification for destructive plugin actions

bash

# Example WAF rule (ModSecurity syntax) to block the vulnerable AJAX action
SecRule REQUEST_URI "@endsWith /wp-admin/admin-ajax.php" \
  "chain,phase:2,deny,status:403,id:1026065049,msg:'Block Ninja Forms nf_delete_all_data'"
  SecRule ARGS:action "@streq nf_delete_all_data"